1. Field of the Invention
The present invention relates to a temperature distribution equalizing structure of a heat roller in a an image forming device such as a laser printer, and more particularly, to a temperature distribution equalizing structure which is capable of preventing, in a simple manner, the temperature on the both ends of a heat roller installed in an image forming device such as a laser printer from being decreased.
2. Description of the Related Art
Generally, a laser printer receives data outputted from a personal computer and outputs the received data as an image. Next, the image, which is formed on paper developed by means of an OPC drum, is fixed by scattering toner on the paper, while passing through a fixing unit. The fixing unit is divided into a heat roller which generates a high temperature and pressure portion which its made of a specific rubber material to apply pressure.
In an earlier laser printer in which a heat roller is installed, there are provided a pair of bearings which are formed on both ends of the heat roller to support the heat roller and a gear which is installed on one end of the heat roller to transmit mechanical power to the heat roller.
In the earlier laser printer, however, since the both ends of the heat roller are open, there occurs a problem in that a great amount of heat loss occurs. It can be appreciated that a temperature difference between the central portion and the left and right end portions of the earlier heat roller is great. This temperature difference results in different toner fixing states between the central portion and the left and right end portions. In other words, the central portion of the heat roller obtains a good fixing state because of its high temperature, and to the contrary, the left and right end portions of the heat roller fail to obtain such a good fixing state, when compared with the central portion.
Moreover, in the earlier laser printer, an erect rod is adapted to support a halogen lamp. In this case, as the halogen lamp is inclined gradually, the surface of the heat roller fails to maintain a uniform temperature distribution. Furthermore, in the case where an additional member is used to support both ends of the halogen lamp, the production cost and the assembling time must be increased, and therefore, the production yield may be decreased.